using Microsoft.Extensions.Logging;
using Microsoft.Win32;
using PatchProbe.Shared.Contracts;
using PatchProbe.Shared.Models;

namespace PatchProbe.Cli.Collectors;

public sealed class OsCollector(ILogger<OsCollector> logger) : ICollector<OsInfo>
{
    private const string CurrentVersionKey = @"SOFTWARE\Microsoft\Windows NT\CurrentVersion";

    public Task<OsInfo> CollectAsync(CancellationToken cancellationToken = default)
    {
        logger.LogInformation("Collecting OS information");

        using var key = Registry.LocalMachine.OpenSubKey(CurrentVersionKey);

        var installDateRaw = key?.GetValue("InstallDate");
        DateTimeOffset? installDate = installDateRaw is int installDateInt
            ? DateTimeOffset.FromUnixTimeSeconds(installDateInt)
            : null;

        var info = new OsInfo
        {
            ProductName = key?.GetValue("ProductName")?.ToString(),
            EditionId = key?.GetValue("EditionID")?.ToString(),
            DisplayVersion = key?.GetValue("DisplayVersion")?.ToString(),
            ReleaseId = key?.GetValue("ReleaseId")?.ToString(),
            BuildNumber = key?.GetValue("CurrentBuildNumber")?.ToString(),
            Ubr = key?.GetValue("UBR") is int ubr ? ubr : 0,
            Architecture = Environment.Is64BitOperatingSystem ? "x64" : "x86",
            InstallDate = installDate,
            LastBoot = GetLastBoot(),
        };

        return Task.FromResult(info);
    }

    private static DateTimeOffset? GetLastBoot()
    {
        try
        {
            var uptime = TimeSpan.FromMilliseconds(Environment.TickCount64);
            return DateTimeOffset.UtcNow - uptime;
        }
        catch { return null; }
    }
}